Not applicable.
Not applicable.
1. Field of the Invention
The present invention concerns a new crystalline form of cabergoline, a pharmaceutical composition thereof and its use as a therapeutically active agent, alone or in combination. Another aspect of the present invention relates to the preparation of this crystalline form.
2. Description of the Related Art
Cabergoline is an ergoline derivative interacting with D2 dopamine receptors and is endowed with different useful pharmaceutical activities and it is used in the treatment of hyperprolactinemia, central nervous system disorders (CNS) and other related diseases.
Cabergoline is the generic name of 1((6-allylergolin-8Beta-yl)-carbonyl)-1-(3-dimethylaminopropyl)-3-ethylurea, described and claimed in U.S. Pat. No. 4,526,892. The synthesis of Cabergoline molecule is reported also in Eur. J. Med. Chem., 24, 421, (1989) and in GB 2,103,603.
During our work we discovered that cabergoline can exist in at least two crystalline forms under ambient conditions. One form (coded Form I) is an anhydrous not solvated form and, to our knowledge, it is the only form reported in the literature to date. Form II is an anhydrous not solvated form too.
Thus, the present invention concerns a new polymorph (Form II) of cabergoline and the preparation thereof. Another aspect relates to samples of cabergoline Form II having a % polymorph purity  greater than 90%, preferably  greater than 99%. The invention further provides a pharmaceutical composition of cabergoline Form II and its use as therapeutic agent.